Using ?tegory%-%postname% possible in Permalink Settings?

I am working on migrating an old site with thousands of posts into WordPress. I’m trying to minimize the number of redirects that will need to made by matching the site’s current permalink structure in a version of Movable Type.

The permalink settings I’m trying to use are:

/archives/%category%-%postname%.html

To be clear, the category and postname are separated by a hyphen, not a slash as frequently used in WP.

Everything here works just fine until a category slug is more than one word, in which case the post’s permalink results in a 404 error. So a category with slug testcategory works, whereas a category with slug test-category doesn’t:

Works: /archives/testcategory-post-title-slug.html
404s: /archives/test-category-post-title-slug.html

I get the 404s on test environments running Apache and a production environment running nginx.

Unfortunately this migration has mostly two word or more categories ??

Does anyone know how to get %category%-%postname% in permalink settings working?